“Throttle” problem causes failed rocket landing
April 21, 2015
By Chris Forrester
Billionaire Elon Musk blamed a slower than expected throttle valve response as causing the first stage of one of his SpaceX rockets to collapse at it hit the floating landing stage. Landing, and then re-using the rocket, is a key part of Musk’s strategy for dramatically trimming the cost of launching satellites into orbit.
SpaceX’s next attempt will be in two months, in June, when SpaceX is making another routine cargo delivery to the International Space Station (ISS). Last week’s attempt was Musk’s third attempt to make a soft landing of the Falcon-9 rocket’s cargo spacecraft. It was returning from the ISS.
The good news is that the rocket almost made it. Indeed, watching the landing video shows that more went right, than wrong, with the landing. As one observer commented in trade mag Launchspace: “It appears the [rocket’s upper stage] was descending a little too fast and the angular body rates were a little too high. The trick in making a successful landing is to vertically descend without any angular rates and decelerate such that the vertical velocity reach zero as the stage settles on the platform.”